Annual herbs (outside the area perennial and shrubby species occur). Leaves alternate, sometimes opposite below, linear to linear-lanceolate, variously tomentose, often more strongly on the upper surface. Capitula usually heterogamous, solitary or variously aggregated; phyllaries pluriseriate, brownish, stereome divided, usually cymbiform and subtending a female floret, the inner flattish and surrounding the bisexual florets (in one subgenus functionally male with aborted ovary). Corolla of female florets filiform, of bisexual cylindric or campanulate, yellow. Style-branches truncate and penicillate in fertile bisexual florets. Anther bases sagittate. Cypselas with globose myxogenic twin hairs; pappus absent in female florets, in the bisexual florets setae shortly plumose in upper part.